There are about 5,000 different species of ladybird in the world. These much loved critters are also known as lady beetle or ladybug, and in many cultures they’re considered good luck. They come in many different colors and patterns, but the most familiar is the seven-spot ladybird, which has a shiny, red-and-black body. Most people like ladybirds because they are pretty, graceful and harmless to humans. But farmers love them because they eat aphids and other plant-eating pests. In it’s year-long life, a single seven-spot ladybird can gobble more than 5000 aphids!
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Coccinellids are often conspicuously coloured yellow, orange, or red with small black spots on their wing covers, with black legs, heads and antennae. There is, however, great variation in these colour patterns. For example, a minority of species, such as Vibidia duodecimguttata, a twelve-spotted species, have whitish spots on a brown background. Coccinellids are found worldwide, with over 6,000 species described.
Most coccinellids have round to elliptical, dome-shaped bodies with six short legs. Depending on the species, they can have spots, stripes, or no markings at all. Seven-spotted coccinellids are red or orange with three spots on each side and one in the middle; they have a black head with white patches on each side.
Their head is black with white patches on either side. The ladybird’s bright colours act as an important defence mechanism, warning animals they’d best not eat them. When threatened, the bugs secrete an oily, yukky, yellow fluid from joints in their legs – and their colouring acts a reminder to any peckish predators who’ve eaten their kind before that they taste disgusting!
Ladybug as friends
Coccinellids are best known as predators of Sternorrhyncha such as aphids and scale insects, but the range of prey species that various Coccinellidae may attack is much wider. A genus of small black ladybirds, Stethorus, presents one example of predation on non-Sternorrhyncha; they specialise in mites as prey, notably Tetranychus spider mites. Stethorus species accordingly are important in certain examples of biological control. They are natural predators of a range of serious pests, such as the European corn borer.
Apart from the generalist aphid and scale predators and incidental substances of botanical origin, many Coccinellidae do favour or even specialise in certain prey types. This makes some of them particularly valuable as agents in biological control programmes.
Birds are ladybugs’ main predators, but they also fall victim to frogs, wasps, spiders and dragonflies.
Ladybirds lay their eggs in clusters or rows on the underside of a leaf, usually where aphids have gathered.
Control when they become unwelcomed
As we know that too much of anything is a problem, similarly too much of ladybugs are a big problem. Ladybug is an example of how an animal might be partly welcome and partly harmful. It was introduced into North America from Asia in 1916 to control aphids, but is now the most common species, out competing many of the native species. It has since spread to much of western Europe, reaching the UK in 2004. It has become something of a domestic and agricultural pest in some regions, and gives cause for ecological concern. It has similarly arrived in parts of Africa, where it has proved variously unwelcome, perhaps most prominently in vine-related crops.
Because they are so beneficial in the garden, it is generally not recommended to kill them in large numbers, yet the indoor infestations can be pretty overwhelming.
Prevention is the best strategy, along with regular removal of current invaders.
Tips for dealing with a ladybug infestation:
- Once ladybugs are in, it’s hard to get them out. Vacuum them up regularly, and either dispose of them or release them back outside. Unlike other household pests, ladybugs come indoors to hibernate, not to multiply and invade. For this reason, many homeowners simply increase their vacuuming during ladybug season and otherwise don’t worry about them.
- Place a knee-high stocking inside the tip of your vacuum-cleaner wand, and secure it to the rim with tape or rubber bands. As you vacuum, the ladybugs will be caught in the stocking. Don’t leave them in your vacuum-cleaner bag; they’ll crawl right back out!
- Try a Lady Bug Light Trap to attract and capture large numbers of ladybugs for release outdoors.
- Seal all cracks and openings around doors, windows, outlets, eaves, pipes, and any place an insect might enter. Don’t underestimate their ability to squeeze in! Use foaming sealants to close up drafty crevices, and apply weather stripping to older doors. This will lower your heating bill, too.
- Don’t try to sweep or otherwise agitate them; when stressed, ladybugs release a yellow, smelly substance that can cause stains.
- In the spring, the beetles will return to the outdoors. Before they return in the fall, you can apply a residual insecticide around the exterior, doors, and windows of your home, to keep them from returning.